122 MARVELS OF FISH LIFE 



fish are not sardines at all. But the small-sized sardine 

 is a one-year-old pilchard, whereas the larger size is 

 merely an older pilchard. 



Of all our food fishes probably the mackerel is the 

 most beautiful, with its alternating zig-zag bands of 

 black and green, its metallic iridescence, ranging from 

 a silvery hue to a coppery gold, and its changing colours 

 from a yellow to a beautiful pink. 



In the spring and early summer mackerel feed on 

 minute free-swimming crustaceans, such as copepods, and 

 mysis (a mysis is illustrated on the plate facing p. 152), 

 and on the medusa-fleas which frequent jelly fish. This 

 food is strained from the water by the gill-rakers of the 

 fish which are as well developed in the mackerel as in 

 the herring. In the late summer and autumn mackerel 

 feed on small pilchards, sprats, rocklings and sand 

 eels. 



The mackerel is a summer spawner, and the floating 

 eggs are found round our shores in May and June. 



The seasonal migrations of this fish have always 

 attracted great interest. Broadly speaking, the mackerel 

 is practically absent from the Cornish coast from Novem- 

 ber to January. With approaching spring it is caught 

 in the Atlantic at first some distance out, but by May 

 huge shoals have come right in shore. These fish are 

 abundant during June and July, but become scarce in 

 August and then disappear. They turn up again for a 

 month late in September, and then again disappear 

 until the following May. 



